University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Architectural Engineering -- Dissertations and Architectural Engineering and Construction, Student Research Durham School of Spring 5-2012 ELECTROMAGNETIC HARVESTING TO POWER ENERGY MANAGEMENT SENSORS IN THE BUILT ENVIRONMENT Evans Sordiashie University of Nebraska-Lincoln, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/archengdiss Part of the Architectural Engineering Commons Sordiashie, Evans, "ELECTROMAGNETIC HARVESTING TO POWER ENERGY MANAGEMENT SENSORS IN THE BUILT ENVIRONMENT" (2012). Architectural Engineering -- Dissertations and Student Research. 18. https://digitalcommons.unl.edu/archengdiss/18 This Article is brought to you for free and open access by the Architectural Engineering and Construction, Durham School of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Architectural Engineering -- Dissertations and Student Research by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. ELECTROMAGNETIC HARVESTING TO POWER ENERGY MANAGEMENT SENSORS IN THE BUILT ENVIRONMENT by Evans Sordiashie A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science Major: Architectural Engineering Under the Supervision of Professor Mahmoud Alahmad Lincoln, Nebraska May, 2012 ELECTROMAGNETIC HARVESTING TO POWER ENERGY MANAGEMENT SENSORS IN THE BUILT ENVIRONMENT Evans Sordiashie, M.S. University of Nebraska, 2012 Adviser: Mahmoud Alahmad Recently, a growing body of scholarly work in the field of energy conservation is focusing on the implementation of energy management sensors in the power distribution system. Since most of these sensors are either battery operated or hardwired to the existing power distribution system, their use comes with major drawbacks. Battery maintenance and associated labor costs can make implementing sensors very expensive. Although hardwired sensors require very little post-installation maintenance, any energy savings they may procure is offset by the amount of energy expended during the course of the sensors normal operation. In response to these energy challenges, this thesis proposes an electromagnetic harvesting device that powers such sensor technologies by scavenging low electromagnetic field energy. First, the quantities of magnetic flux densities around common current carrying conductors in the built environment are estimated according to the equivalent amount of power that can be generated. Then, a prototype of the harvesting device for scavenging low magnetic flux is designed and developed. Finally, the device is evaluated for real-world implementation using a novel prototype board. iii ACKNOWLEDGEMENT I would like to thank my adviser, Dr. Mahmoud Alahmad, for his continued support and presence as a source of advice, guidance, and assistance during my academic career. I would also like to extend my appreciation to my research colleague, Timothy Wisnieski for his continued support throughout this research. iv DEDICATION I would like to dedicate this work to my wonderful family who are my inspiration, my happiness, and my source of energy. v GRANT INFORMATION This project is funded and sponsored by the Durham School of Architectural Engineering and Construction. vi TABLE OF CONTENTS GRANT INFORMATION ............................................................................................................... v LIST OF FIGURES ...................................................................................................................... viii LIST OF TABLES .......................................................................................................................... ix INTRODUCTION ........................................................................................................................... 1 1.1 Motivation ........................................................................................................................ 1 1.2 Problem Formulation ....................................................................................................... 3 1.3 Research Goals................................................................................................................. 6 1.4 Thesis Overview .............................................................................................................. 7 BACKGROUND ............................................................................................................................. 8 2.1 Energy Harvesting System ..................................................................................................... 8 2.1.1 Energy Sources ............................................................................................................... 8 2.1.2 Converting Processes .................................................................................................... 11 Photovoltaic Harvesting ......................................................................................................... 12 Thermogenerator .................................................................................................................... 12 Piezoelectric Harvester .......................................................................................................... 12 RF Energy Harvester (Rectenna) ........................................................................................... 13 Electromagnetic Harvester ..................................................................................................... 13 2.1.3 Load .............................................................................................................................. 14 2.2 Related Work ....................................................................................................................... 14 AN OVERVIEW OF ELECTROMAGNETICS & TRANSFORMERS ...................................... 21 3.1 Introduction .......................................................................................................................... 21 3.2 Overview of Electromagnetics ............................................................................................. 21 3.2.1 Biot-Savart Law ............................................................................................................ 22 3.2.2 Ampere's Law and Magnetic Flux Density ................................................................... 24 3.2.3 Ferromagnetic Materials ............................................................................................... 25 3.3 An Overview of Electrical Transformers ............................................................................. 27 3.3.1 Current Transformers (CT) ........................................................................................... 30 3.3.2 Transformer Core Saturation ........................................................................................ 34 RESEARCH OBJECTIVE, METHODOLOGY, AND DESIGN ................................................. 36 4.1 Introduction .......................................................................................................................... 36 4.2 Research Objective and Methodology ................................................................................. 36 4.3 The Design Process .............................................................................................................. 40 vii 4.3.1 Design Calculations ............................................................................................... 41 RESULTS AND DISCUSSION .................................................................................................... 49 5.1 Introduction .......................................................................................................................... 49 5.2 Electromagnetic Energy Around Current Carrying Conductors .......................................... 50 5.3 Induced and DC Output Voltages ........................................................................................ 52 5.4 Core Size, Versus Magnetic Flux and Input Load Current .................................................. 55 5.6 Simulation vs. Experimental Results ................................................................................... 62 5.7 Discussion ............................................................................................................................ 63 TECHNICAL CHALLENGES, BENEFITS AND OPPORTUNITIES ........................................ 65 6.1 Introduction .......................................................................................................................... 65 6.2 Challenges ............................................................................................................................ 65 6.3 Benefits ................................................................................................................................ 66 6.4 Opportunities ....................................................................................................................... 67 CONCLUSION AND RECOMMENDATIONS........................................................................... 69 7.1 Future Research ................................................................................................................... 70 APPENDICES ..............................................................................................................................